June 17 (Reuters) - Zueblin Immobilien Holding AG : * Has been informed by Lamesa Holding SA that Lamesa has bought from Forum Group a substantial shareholding in Zueblin Immobilien Holding * Says Lamesa Holding SA has said it made an offer for the French mandatory convertible bond, issued by Zueblin Immobiliere France SA and held by Forum Group * Zueblin Immobilien Holding says Bruno Schefer to resign as CEO effective as of end of July 2014 as contribution for new start of Zueblin * Source text for Eikon * Further company coverage